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Finding the Fourth Proportional to 78.10, 118.00 and 77.35

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Solution

The fourth proportional to 78.10, 118.00 and 77.35 is: 116.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.10 : 118.00 = 77.35 : x
  2. Step 2: Convert to fraction form
    78.10/118.00 = 77.35/x
  3. Step 3: Cross multiply
    78.10x = 118.00 × 77.35
  4. Step 4: Simplify right side
    78.10x = 9,127.21
  5. Step 5: Solve for x
    x = 9,127.21/78.10
  6. Step 6: Final answer
    x = 116.87

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.